It's 刀. I can't actually see where it says the radical is 巾 on that website. The radical that is 'biggest' or more dominant is the radical it's sorted by, but you can also search by not dominant radicals (sword, broom (backwards 'E'), crown and towel.)
Heisig's method teaches you all about radicals, completely free - that's what I used :)
Heisig doesn't tell you what "the" radical of a kanji is, so that's not relevant. For 帰 I think it's indeed listen under 巾 in dictionaries.
OK thank you!
Both are correct. It depends on which kanji dictionary you are reading. I found this Q&A about it: http://kanjibunka.com/kanji-faq/old-faq/q0184/
I'll try to summarise:
Modern Japanese kanji dictionaries take their radical information from 康熙字典 (the Kangxi dictionary). This dictionary was compiled before 帰 got it's current form. It evolved from 歸, which has the radical 止. But 止 is not present in modern 帰, so it's up to the kanji dictionary editors to pick the radical, and they end up choosing different radicals for 帰.
For example the 漢字源 dictionary lists 刀 as the radical, whereas 新漢語林 lists 巾 as the radical.
Thanks this was interesting.
Yeah it's one of those examples of how written language can be hard to classify strictly :)
Radical of 帰
Hello! Please explain me why the radical is 刀 there http://jisho.org/search/%E5%B8%B0%20%23kanji
while there the radical is 巾 http://kakijun.jp/page/1055200.html
Who's right?